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If you want to extend or open up the back of your home, bifold doors might well be at the top of your list to bring in more daylight and create a connection between indoors and out. But there’s more to bifolds than simply creating a moveable glass wall: how many panels do you need, for instance, and where should they stack? Do you need a master access door and how can it be incorporated?
Manufacturing improvements also mean that you can have much larger glass panels than you could just a few years ago, adding to the flexibility folders offer. Here’s what you need to know when settling on the perfect configuration for your project.
Your architect or project designer will likely have a handle on the key pros and cons of bifold doors versus other types – such as glazed sliders and glazed pivoting doors – and basic considerations on how to integrate them. Their advice could help cement your enthusiasm for one system over another, but when it comes to the detail, they won’t go much further than plonking a copy-and-paste element into your floorplans.
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A two-panel Kloeber KustomFold aluminium external bifold combines with the company’s InterFold internal doors on this project. The flow of the room and access from the playroom to lounge dictated that the InterFolds should stack towards the wall, so they don’t stick out into a thoroughfare
“A lot of architects get it wrong on configuration, partly because they’re quite generic in their drawings,” explains Phil Dascombe, technical director at Kloeber. As a result, it’s a familiar feeling for glazed door specialists to be greeted by customers who want a very specific arrangement that, on closer inspection, turns out to be less-than-ideal for meeting their lifestyle and performance goals.
One classic criticism of bifolds is that, when closed, there’s much more view-obscuring frame on display than you’d get with sliders. These thicker sightlines will also cut down on the amount of light that can flood through into your home’s interiors.
Sieger Systems‘ 120 aluminium bifold door range can accommodate up to 14 sashes, each a maximum size of 1.2m wide by 3m high. Shown here in a three-panel arrangement with traffic door and flush threshold
“On her show New Life in the Country, Sarah Beeny claimed that nobody gets folders anymore,” says Phil. “Yet we still sell an unbelievable amount of them. People were pushed towards sliding patio doors because of the big glazed panels, but a number of companies can now do XL-sized bifolds with panels as much as 1,500mm wide.” This means you can achieve a 4.5m span with just three folding leafs.
Why is bigger better? Well, just imagine that your planning or Building Regulations drawings show a four-panel, 3.5m configuration. Go ahead and order your bifolds in that arrangement without first speaking to a specialist, and you’ll be buying a product with individual doors around 875mm wide. “By switching to three panels each just under 1,200mm wide, you’ll get more glass and lot less frame,” explains Edward Stobart, technical sales manager at IDSystems.
This bi-parting, six-panel arrangement was completed with Solarlux’s Ecoline system, which offers a slim panel joint of 99mm when the doors are closed
The effect is even more pronounced when dealing with broader apertures, hence why IDSystems rarely fits folders with more than five panels these days. “A 10-panel bifold would require over a metre of aluminium intermediate framing; whereas a four-panel sliding door could achieve the same with less than 8cm of visible sightlines,” says Edward.
QUICK GUIDE Common bifold door configurationsBifold door arrangements are typically identified with a three-digit code. The first number relates to the total number of panels; the second to the number that open to the left; and the third to those that open right. So, a two-door configuration folding left would be 2-2-0, while a four-door where three stack to the left and a master door opens right would be 4-3-1. Here are some popular bifold options and how they work: Two doors: both folding (2-2-0 or 2-0-2)On smaller openings where you’d prefer a modern system rather than traditional French doors, bifolds give a similarly clear opening, with the panels stacked on a single side. Three doors: all folding with optional master (3-3-0 or 3-0-3)An odd number of panels gives you the ability to have all the doors opening in the same direction – including the traffic door, which clips back against the adjacent panel when used individually. Three doors: two folding with separate master (3-2-1 or 3-1-2)This style essentially combines a two-panel bifold with a master door opening in the opposite direction. It’s relatively rare, as you lose the ability to fold all of the panels together; though might be useful if you really need them to stack at separate ends. Four doors: all folding (4-4-0 or 4-0-4)Bifolds work in pairs, so if you have an even number of doors and want the drama of them all folding one way (whether right or left), you can’t have a panel that operates on its own as a master. Four doors: three folding, one master (4-3-1 or 4-1-3)To create a lead door in an even-numbered bifold, you’ll need to split the run into odd numbers. So, in a four-panel design, three will fold to one side, while the other opens in the opposite direction like a standard hinged door. Four doors: centre-parting (4-2-2)With two panels folding left and two to the right from the centre of the run, this configuration gives you that big French door-style reveal when you open the panels. It also means you can have a slimmer stack at both ends rather than one chunky concertina. |
You won’t just benefit from a superior outlook by using wider doors. It should represent better value-for-money, too. “With bifolds, much of the cost is in the profile and manufacture,” says Phil. “If a house designer specifies a five-panel set for a 4m opening that could be done with four, the homeowner could be spending £1,500 more than they need to.”
Spanning an opening 3.3m wide and 2.35m tall, this three-panel RF1200 outward-opening bifold from Renka features an independent traffic door and is finished in RAL7021 (black grey)
Edward agrees: “Factory-assembling a big frame costs the same as it does to put a smaller one together. Most bifolds are charged per panel, so you’re generally better off going for fewer, larger doors – particularly if the opening size isn’t set in stone yet. The one exception is if you have limited space on a patio, as having more, smaller panels means that the stack won’t extend out from the wall as far.”
When you come to specify your glazed doors, you’ll probably be focussed on how great it will be to fling the doors open on gorgeous summer days to bring in tonnes of fresh air and enjoy the garden to its fullest. Few people consider what it might be like when you need to gain access to the garden in the rain or over winter.
That’s where a master door (also known as a lead or traffic door) comes in. With this arrangement, one of the panels can be operated individually just like a traditional door. If you need to pop outside, you can open-and-close it in seconds, preventing heat leaking out from your living spaces. “Particularly on extension projects in urban areas, where the bifolds might be the only access, having a master door just makes so much sense,” says Edward.
The XP Vision range from Express Bi-folding Doors offers individual panel widths of up to 1,500mm and heights of up to 3,300mm. This enables configurations of 4.5m in just three panels, 6m in four panels and 7.5m in seven panels
The neatest way to incorporate a traffic door is on an odd-numbered bifold configuration, so it can fold with the rest of the run or operate as a standalone. “If the master is within a set of three or five panels, it can hinge with the folders and clip back securely against the adjacent door when you open it,” says Phil. “On a four-panel, the lead opens in the opposite direction, so you would need a cabin hook or floor-mounted door holder to keep it in place.”
What’s more, on an even-numbered configuration, the locking mechanism will need to be accommodated where the traffic door meets the folder. “This would mean you need a chunkier profile here, so the intermediate frames won’t all be the same width,” says Edward.
When you open your bifolds, those lovely glass panels have to go somewhere – so you’ll need to decide whether they should stack internally or externally. This isn’t just about where the doors end up sitting once folded: as they concertina, the hinged edges need to travel on one side or the other of the track, meaning you need to ensure the whole zone is kept clear.
This renovation and extension in Cambridge features a four-panel set of Sunflex bifold doors from IDSystems in a one left, three right configuration. Four panels were selected in order to minimise the intrusion on to the small patio (in comparison to three wider panels), when the doors are opened
Outward-opening is the most common choice on ground floors, leaving you with maximum living space and the flexibility to position internal furniture pretty much wherever you wish. It’s also better for the British weather.
“If it’s been raining, the last thing you want is to open wet doors internally over your carpet or suchlike,” says Edward. It’s not the right choice for every project, however. If your bifolds will open up onto a small patio, for instance, you might prefer an internal stack. “Probably 99% of the inward-opening doors we do are for first floor balconies; either because it’s a Juliette or you want a little table and chair out there and the space is just too small for outward opening.”
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